Gas hydrates, chemical compounds of water and natural gas, are increasingly being studied for their potential to be huge reservoirs of energy, possibly causing sea floor instability, and significant contributors to global warming.





A. to be huge reservoirs of energy, possibly causing sea floor instability, and
B. to be huge reservoirs of energy, possibly causing sea floor instability, and even as
C. as huge reservoirs of energy, possibly causing sea floor instability, and
D. as huge reservoirs of energy, and the possible cause of sea floor instability
E. as huge reservoirs of energy, as possible causes of sea floor instability, and even as


What do you think is the correct answer?
Is it the question being asked of regarding the parallel or being approached by semantic meaning. I would choose A but the E is the strong candidate for the correct answer though. Is anybody who has confidence in the correct answer on it?